Dentists constantly remind patients to brush their teeth well, including the tongue. But as any brusher knows, an errant stroke to the back of the tongue triggers a gag reflex, which also causes the eyes to tear. But why should a stimulus applied in the oral cavity––the opening of the gastrointestinal tract––have any effect on the eyes? Could evolutionary mechanisms have caused the effect or does intelligent agency better explain it? Imagine if, when touching the tongue, one would always hear a particular bell tone, or smell an aroma, or feel the hands or feet become cold as ice or hot as fire, or see temporarily only in hues of black and white? Such anomalous crossings of stimulation with sensation are termed synesthesia. Viewed differently, imagine the engine in a car becoming hotter, but instead of the coolant gauge rising, the radio volume becomes louder. Such a phenomenon would surely send the owner back to the dealer for some warranty repairs. But when the human eyes tear because we have been gagged, it is not an anomaly but a normal function. How did this process come about?
Reflex tearing has been well understood for decades.1 It refers to tearing in response to tactile stimulation of the surface of the eye.2 Bogorad’s syndrome,3 colloquially known as “crocodile tears syndrome,” is an anomaly of function due to damage of the facial nerve that results in tearing not when touching the eye, but when the sufferer simply eats. Here, a normal phenomenon is triggered in a way entirely different from what might be expected. Though scientists have understood the anatomy and physiology of reflex tearing, how it came about is quite another matter. What purpose could there be for what I shall call the gag lacrimal gland reflex (GLGR)?
Consider that a gag reflex is frequently associated with a violent expulsion of the stomach’s contents, or vomiting (emesis). The stomach, in addition to digestive enzymes called proteases, contains hydrochloric acid (also known as muriatic acid), which “is a highly corrosive, strong mineral acid with many industrial uses.”4 If the ailing person gets some of this mix on the skin quick action should be taken to prevent injury—yet this “alien-blood-like” stuff doesn’t burn a hole in the stomach. Now, when one vomits one also reflexively bends over, bringing the mouth closer to the ground. Also, the force of the expulsion may result in splashing of the acidic mix, thereby leaving the eyes vulnerable to injury. But we need not worry because our lacrimal glands spring into action by emptying their stores––effectively hosing down our eyes with tears to help protect them.
This elegant process demonstrates every bit of the same understanding, forethought, and purpose that an aviation emergency response team does. Envision a commercial airliner with malfunctioning landing gear approaching an airport. The crew has decided to undergo the harrowing experience of an emergency belly landing. The airport prepares for the worst by readying fire crews, dispatching convoys of ambulances and EMT personnel, notifying hospitals, and taking the precaution of applying foam to the runway to serve as a retardant for the expected sparks and ignition of possible fire. The plane lands safely due to coordinated effort and engineering.
A belly-landing airplane is not exactly the same as an upset belly, but the same type of intelligence applies. Just as agents mobilize to prevent disaster, so too does the GLGR reduce injury to our highly specialized and vulnerable eyes. One might liken the stomach’s acidic mix to sparks and ignition under the plane’s belly and lacrimal glands secreting tears to firefighters hosing down a runway with fire-retardant foam.
Engineers refer to such an interconnected design trait in an artifact as a System of Systems (SoS). Many designed products––from a watch or piano to a city or Apollo moon rocket––feature such integrated systems to varying degrees, but they are also found in every living organism and often exhibit higher complexity.
The GLGR shows the complex interaction of three organ systems: the gastrointestinal, ophthalmic, and autonomic nervous systems, plus the musculoskeletal (bending over). However, SoS is evident too at the levels of a single organ, the tissue of an organ, the cells of the tissues, and even the subcellular organelle level as revealed by the sciences of physiology, histology, cell and molecular biology, and biochemistry. In fact, the proposition that the universe, humanity, and all other life-forms exist due to the agency of an intelligent Creator would expect evidence of intelligence to be found throughout the physical realm, from the subatomic to the galactic to large-scale structures of the universe. The observations of science support this proposition repeatedly.
To think that such design could result apart from intelligence stretches credulity. Adherents of the neo-Darwinian evolutionary paradigm frequently argue their case by arranging life in artificially imposed orders of increasing complexity by parts (anatomy). However, they do not offer evidence for the evolution of processes (physiology) and behaviors that would theoretically need to be beneficial for survival at every minutely incremental step along the way. Such evidence might cause dyspepsia for the evolutionary biological mantra of “anatomy determines physiology” or “form determines function.” The same data would reveal purposeful design and affirm what all engineers know to be true: “Necessity is the mother of invention” or “function determines form!”
1. J. R. Mutch, “The Lacrimation Reflex,” British Journal of Ophthalmology 28 (July 1944), 317–36.
2. Michael E. Stern et al., “A Unified Theory of the Role of the Ocular Surface in Dry Eye,” in Lacrimal Gland, Tear Film, and Dry Eye Syndromes 2: Basic Science and Clinical Relevance, ed. David A. Sullivan, Darlene A. Dartt, and Michele A. Meneray (New York: Plenum, 1998). See the neurological pathway for reflex tearing at page 647, but note the absence of sensory input from the oral cavity.
3. F. A. Bogorad and Austin Seckersen, “The Symptom of Crocodile Tears,” Journal of the History of Medicine and Allied Sciences 34 (January 1979): 74–79.
4. Wikipedia, s.v. “hydrochloric acid,” last modified July 15, 2014, http://en.wikipedia.org/wiki/Hydrochloric_acid.
By Dr. Eddy M. del Rio
Dr. Eddy M. del Rio received his MD from Saint Louis University in 2004, and currently serves as a practicing physician for the Veterans Health Administration in the greater Springfield, MO region.